scholarly journals Aldosterone Production and Insulin Resistance in Healthy Adults

2010 ◽  
Vol 95 (4) ◽  
pp. 1986-1990 ◽  
Author(s):  
Rajesh Garg ◽  
Shelley Hurwitz ◽  
Gordon H. Williams ◽  
Paul N. Hopkins ◽  
Gail K. Adler

Abstract Context: Aldosterone production is associated with insulin resistance in obese and hypertensive subjects. However, its effect on insulin sensitivity in healthy subjects is not clear. Objective: The objective of this study was to test the hypothesis that increased aldosterone production is associated with lower insulin sensitivity in healthy subjects. Design: This is an analysis of data previously collected during studies conducted as part of the International Hypertensive Pathotype Consortium. Participants and Interventions: Eighty-four subjects free of any medical or psychiatric illness were included in this study. They were studied after 7 d of a standardized high-sodium diet confirmed by 24-h urine sodium above 200 mEq. Insulin sensitivity index (ISI) was calculated after a 75-g oral glucose load with glucose and insulin measurements at 0, 30, 60, and 120 min. Serum aldosterone levels were measured after 45 min of angiotensin II (3 ng/kg/min) infusion. Results: There were significant negative correlations between ISI and age, body mass index (BMI), diastolic blood pressure, and angiotensin II-stimulated aldosterone level (P < 0.01). On multivariate regression analysis, stimulated aldosterone level was an independent predictor of ISI after adjusting for age, BMI, and diastolic blood pressure. Stimulated aldosterone level predicted 8% of the variance in ISI (P = 0.003) with age, BMI, and diastolic blood pressure together predicting 23% of the variance in ISI. Thus, the final regression model predicted 31% of the variance in ISI (P < 0.0001). Conclusions: Aldosterone production is associated with insulin resistance in normotensive healthy subjects independent of traditional risk factors.

2002 ◽  
Vol 93 (6) ◽  
pp. 2112-2121 ◽  
Author(s):  
Gunvor Ahlborg ◽  
Jonas Lindström

Cardiovascular diseases are characterized by insulin resistance and elevated endothelin (ET)-1 levels. Furthermore, ET-1 induces insulin resistance. To elucidate this mechanism, six healthy subjects were studied during a hyperinsulinemic euglycemic clamp during infusion of (the ET-1 precursor) big ET-1 alone or after ETA- or ETB-receptor blockade. Insulin levels rose after big ET-1 with or without the ETB antagonist BQ-788 ( P < 0.05) but were unchanged after the ETA antagonist BQ-123 + big ET-1. Infused glucose divided by insulin fell after big ET-1 with or without BQ-788 ( P < 0.05). Insulin and infused glucose divided by insulin values were normalized by ETA blockade. Mean arterial blood pressure rose during big ET-1 with or without BQ-788 ( P < 0.001) but was unchanged after BQ-123. Skeletal muscle, splanchnic, and renal blood flow responses to big ET-1 were abolished by BQ-123. ET-1 levels rose after big ET-1 ( P< 0.01) in a similar way after BQ-123 or BQ-788, despite higher elimination capacity after ETA blockade. In conclusion, ET-1-induced reduction in insulin sensitivity and clearance as well as splanchnic and renal vasoconstriction are ETA mediated. ETA-receptor stimulation seems to inhibit the conversion of big ET-1 to ET-1.


Author(s):  
Malgorzata Malczewska-Malec ◽  
Iwona Wybranska ◽  
Iwona Leszczynska-Golabek ◽  
Lukasz Partyka ◽  
Jadwiga Hartwich ◽  
...  

AbstractThis study analyzes the relationship between risk factors related to overweight/obesity, insulin resistance, lipid tolerance, hypertension, endothelial function and genetic polymorphisms associated with: i) appetite regulation (leptin, melanocortin-3-receptor (MCR-3), dopamine receptor 2 (D2R)); ii) adipocyte differentiation and insulin sensitivity (peroxisome proliferator-activated receptor-γThe 122 members of 40 obese Caucasian families from southern Poland participated in the study. The genotypes were analyzed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) or by direct sequencing. Phenotypes related to obesity (body mass index (BMI), fat/lean body mass composition, waist-to-hip ratio (WHR)), fasting lipids, glucose, leptin and insulin, as well as insulin during oral glucose tolerance test (OGTT) (4 points within 2 hours) and during oral lipid tolerance test (OLTT) (5 points within 8 hours) were assessed. The insulin sensitivity indexes: homeostasis model assessment of insulin resistance, whole body insulin sensitivity index, hepatic insulin sensitivity and early secretory response to an oral glucose load (HOMA-IR, ISI-COMP, ISI-HOMA and DELTA) were calculated.The single gene mutations such as CWe conclude that the polymorphisms we investigated were weakly correlated with obesity but significantly modified the risk factors of the metabolic syndrome.


2013 ◽  
Vol 304 (4) ◽  
pp. R313-R320 ◽  
Author(s):  
Fatima L. C. Sardinha ◽  
Flavia S. Fernandes ◽  
Maria G. Tavares do Carmo ◽  
Emilio Herrera

Prenatal and early postnatal nutritional status may predispose offspring to impaired glucose tolerance and changes in insulin sensitivity in adult life. The long-term consequences of changes in maternal dietary fatty acid composition were determined in rats. From day 1 until day 12 of pregnancy, rats were given isocaloric diets containing 9% nonvitamin fat based on soybean, olive, fish (FO), linseed, or palm oil. Thereafter, they were maintained on the standard diet; offspring were studied at different ages. Body weight at 4, 8, and 12 mo and lumbar adipose tissue and liver weights at 12 mo did not differ between females on the different diets, whereas in males the corresponding values were all lower in the offspring from the FO group compared with the other dietary groups. Plasma glucose concentrations (both basal and after an oral glucose load) did not change with sex or dietary group, but plasma insulin concentrations were lower in females than in males and, in males, were lowest in the FO group. Similar relations were found with both the homeostasis model assessment of insulin resistance and insulin sensitivity index. In conclusion, the intake of more n–3 fatty acids (FO diet) during early pregnancy reduced both fat accretion and age-related decline in insulin sensitivity in male offspring but not in females. It is proposed that the lower adiposity caused by the increased n–3 fatty acids during the intrauterine life was responsible of the lower insulin resistance in male offspring.


2004 ◽  
Vol 287 (5) ◽  
pp. E948-E954 ◽  
Author(s):  
Chi-Chang Juan ◽  
Yi-Wen Shen ◽  
Yueh Chien ◽  
Yen-Jie Lin ◽  
Shau-Feng Chang ◽  
...  

We previously showed that chronic insulin infusion induces insulin resistance, hyperendothelinemia, and hypertension in rats (C. C. Juan, V. S. Fang, C. F. Kwok, J. C. Perng, Y. C. Chou, and L. T. Ho. Metabolism 48: 465–471, 1999). Endothelin-1 (ET-1), a potent vasoconstrictor, is suggested to play an important role in maintaining vascular tone and regulating blood pressure, and insulin increases ET-1 production in vivo and in vitro. In the present study, BQ-610, a selective endothelin A receptor antagonist, was used to examine the role of ET-1 in insulin-induced hypertension in rats. BQ-610 (0.7 mg/ml; 0.5 ml/kg body wt) or normal saline was given intraperitoneally two times daily for 25 days to groups of rats infused with either saline or insulin (2 U/day via sc-implanted osmotic pumps), and changes in plasma levels of insulin, glucose, and ET-1 and the systolic blood pressure were measured over the experimental period, whereas changes in insulin sensitivity were examined at the end of the experimental period. Plasma insulin and ET-1 levels were measured by RIA, plasma glucose levels using a glucose analyzer, systolic blood pressure by the tail-cuff method, and insulin sensitivity by an oral glucose tolerance test. Our studies showed that insulin infusion caused sustained hyperinsulinemia in both saline- and BQ-610-injected rats over the infusion period. After pump implantation (2 wk), the systolic blood pressure was significantly higher in insulin-infused rats than in saline-infused rats in the saline-injected group (133 ± 3.1 vs. 113 ± 1.1 mmHg, P < 0.05) but not in the BQ-610-injected group (117 ± 1.2 vs. 117 ± 1.8 mmHg). Plasma ET-1 levels in both sets of insulin-infused rats were higher than in saline-infused controls (2.5 ± 0.6 and 2.5 ± 0.8 vs. 1.8 ± 0.4 and 1.7 ± 0.3 pmol/l, P < 0.05). Oral glucose tolerance tests showed that BQ-610 treatment did not prevent the insulin resistance caused by chronic insulin infusion. No significant changes were found in insulin sensitivity and blood pressure in saline-infused rats treated with BQ-610. In a separate experiment, insulin infusion induced the increase in arterial ET-1 content, hypertension, and subsequent plasma ET-1 elevation in rats. These results suggest that, in the insulin infusion rat model, ET-1 plays a mediating role in the development of hypertension, but not of insulin resistance.


2003 ◽  
Vol 89 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Louise M. Goff ◽  
Gary S. Frost ◽  
Gavin Hamilton ◽  
E. Louise Thomas ◽  
Waljit S. Dhillo ◽  
...  

Subjects with insulin resistance have been shown to have higher storage levels of intramyocellular lipid (IMCL) than their insulin-sensitive counterparts. It has been proposed that elevated IMCL stores may be the main cause of insulin resistance. The aim of the present study was to ascertain whether there is a causal relationship between IMCL storage and insulin resistance. IMCL storage was assessed using magnetic resonance spectroscopy and insulin sensitivity was assessed by performing an oral glucose tolerance test. A 4-week intervention of reduction of dietary glycaemic index was used to manipulate insulin sensitivity in a cohort of healthy volunteers; the effects of this intervention on IMCL were measured after 4 weeks of intervention. Significant improvements in the insulin sensitivity index occurred following the dietary intervention (baseline 7·8 (sem 1·11) v. post-intervention 9·7 (sem 1·11), P=0·02). However, there were no changes in IMCL storage levels, suggesting that insulin sensitivity can be manipulated independently of IMCL. This suggests that in healthy volunteers, insulin sensitivity is independent of IMCL storage and the high storage levels that have been found in insulin-resistant subjects may occur as a consequence rather than a cause of insulin resistance.


2002 ◽  
Vol 283 (2) ◽  
pp. H562-H567 ◽  
Author(s):  
Denise M. Galipeau ◽  
Linfu Yao ◽  
John H. McNeill

Hyperinsulinemia and insulin resistance have been linked to hypertension; however, the influence of sex on this relationship has not been well studied. The purpose of this experiment was to compare the effects of chronic insulin treatment on insulin sensitivity and blood pressure in male and female rats. Male and female Wistar rats were treated with insulin (2 U/day) via subcutaneous sustained release implants for 5 wk. Systolic blood pressure was measured via the tail-cuff method before and after treatment, and insulin sensitivity was assessed with an oral glucose tolerance test. The insulin sensitivity of female rats was 4.5-fold greater than male rats. Chronic insulin treatment impaired insulin sensitivity in both sexes; however, this occurred to a greater degree in male rats. Blood pressure increased in male rats treated with insulin only. The results demonstrate that hyperinsulinemia and insulin resistance are associated with hypertension in male rats only. Therefore, the link between these conditions appears to depend on sex.


1998 ◽  
Vol 83 (12) ◽  
pp. 4284-4288
Author(s):  
Robert A. Phillips ◽  
Lawrence R. Krakoff ◽  
Andrea Dunaif ◽  
Diane T. Finegood ◽  
Richard Gorlin ◽  
...  

Because left ventricular (LV) mass (LVM) is a powerful predictor of future cardiovascular events, it is important to identify hemodynamic and nonhemodynamic factors that increase LVM. We studied the separate contribution to LVM of daily arterial blood pressure (BP) and insulin resistance in a consecutive series of 29 (mean ± sd age, 43 ± 13 yr) nonobese (body mass index, 24 ± 1.8 kg/m2), nondiabetic, glucose-tolerant subjects with untreated borderline or mild hypertension. The insulin sensitivity index (SI) was quantitatively determined from the frequently sampled iv glucose tolerance test. BP was characterized by ambulatory 24-h BP monitoring, and LVM index (LVMI) was determined by two-dimensional directed M-mode echocardiography. LVMI was directly related to 24-h mean BP (r = 0.47; P = 0.01). LMVI was also significantly related to SI (r = −0.43; P = 0.02). In this nonobese group, neither LVMI nor SI was related to body mass index or age. After adjustment for the influence of BP on LVMI, a significant relation remained between LVMI and SI (P &lt; 0.05). We conclude that in nonobese subjects with high normal BP, insulin sensitivity is related to LVM independently of BP and may be an important modulator of LV growth. In addition to a reduction of arterial BP, optimal prevention of LV hypertrophy in hypertensives may require improved insulin sensitivity.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 350-351
Author(s):  
Hector H Salgado ◽  
Aline Remus ◽  
Marie-Pierre Letourneau-Montminy ◽  
Candido Pomar

Abstract Growing pigs’ body composition variation can be associated with differences in insulin sensitivity given the insulin anabolic effect on protein and lipid synthesis. The objective of this study was to elucidate this association by relating the individual insulin response to the oral glucose tolerance test (OGTT) with the body composition of growing pigs. Thirty 95 kg jugular vein catheterized pigs received an oral dose of 1.75 g of glucose/kg of BW after 18 hours of fasting. Blood samples were collected at -20, -10, 5, 10, 15, 20, 25, 30, 45, 60, 90, 120, 150, 180, 210, 240, 300 and 360 min following glucose ingestion. Insulin sensitivity indexes were calculated and analyzed. Body lipids (LB, %) and protein (PB, %) composition were estimated by dual X-ray densitometry. Association between body composition and insulin sensitivity were studied by using partial least squares and correlations. Average LB and PB were 19.7% (CV = 7.6 %) and 16.2% (CV = 2.2%), respectively. Basal insulin blood concentration and area-under-the-curve (AUC) CV (51.9 % and 26.9 %, respectively) were larger than those for basal glucose and AUC (5.52 and 5.48 %, respectively). Additionally, insulin sensitivity (%S), steady-state beta cell function (%B), and insulin resistance (HOMA-IR) estimated with the Homeostasis Model Assessment (HOMA 2) and whole-body insulin sensitivity index (ISI) were highly variable between pigs which CV ranged from 30.1 % to 54.5 %. These results can indicate an early stage of insulin resistance in an important part of the studied pig population. LB and PB were affected by insulin sensitivity indexes (P &lt; 0.05) which accounted, respectively, for 48% and 44% of the observed variation. In conclusion, lower insulin sensitivity was associated with higher body fat in growing pigs raised under similar conditions.


2020 ◽  
Vol 318 (3) ◽  
pp. E381-E391 ◽  
Author(s):  
Julie Lacombe ◽  
Omar Al Rifai ◽  
Lorraine Loter ◽  
Thomas Moran ◽  
Anne-Frédérique Turcotte ◽  
...  

Osteocalcin (OCN) is a bone-derived hormone involved in the regulation of glucose metabolism. In serum, OCN exists in carboxylated and uncarboxylated forms (ucOCN), and studies in rodents suggest that ucOCN is the bioactive form of this hormone. Whether this is also the case in humans is unclear, because a reliable assay to measure ucOCN is not available. Here, we established and validated a new immunoassay (ELISA) measuring human ucOCN and used it to determine the level of bioactive OCN in two cohorts of overweight or obese subjects, with or without type 2 diabetes (T2D). The ELISA could specifically detect ucOCN concentrations ranging from 0.037 to 1.8 ng/mL. In a first cohort of overweight or obese postmenopausal women without diabetes ( n = 132), ucOCN correlated negatively with fasting glucose (r = −0.18, P = 0.042) and insulin resistance assessed by the homeostatic model assessment of insulin resistance (r = −0.18, P = 0.038) and positively with insulin sensitivity assessed by a hyperinsulinemic-euglycemic clamp (r = 0.18, P = 0.043) or insulin sensitivity index derived from an oral glucose tolerance test (r = 0.26, P = 0.003). In a second cohort of subjects with severe obesity ( n = 16), ucOCN was found to be lower in subjects with T2D compared with those without T2D (2.76 ± 0.38 versus 4.52 ± 0.06 ng/mL, P = 0.009) and to negatively correlate with fasting glucose (r = −0.50, P = 0.046) and glycated hemoglobin (r = −0.57, P = 0.021). Moreover, the subjects with ucOCN levels below 3 ng/mL had a reduced insulin secretion rate during a hyperglycemic clamp ( P = 0.03). In conclusion, ucOCN measured with this novel and specific assay is inversely associated with insulin resistance and β-cell dysfunction in humans.


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